An upstate judge is in hot water for calling Assembly Speaker Sheldon Silver a “slug” in The Post’s pages.

The state Commission on Judicial Conduct last week hauled Cattaraugus County Judge Larry Himelein, 60, before a referee on undisclosed charges.

Himelein admits he used the epithet to describe the Lower East Side Democrat over long-stalled pay raises for New York judges — but insists he did so in a leaked e-mail to fellow judges, not in an April 2008 phone interview with The Post in which he confirmed he was refusing to hear cases involving Weitz & Luxenberg, Silver’s employer.

The commission is also probing whether he said, “I think the speaker is a slug.” Subpoenaed Post reporter Bruce Golding testified his report was accurate.

A lawyer not involved in the case said Himelein was likely to get just a private warning if convicted of detracting “from the dignity of judicial office.”

But if found to have misled the panel, he faces tougher sanctions, including possible removal, the source said.